Core Definition and 484 Threads

Homework Statement A coil is connected in series with a bulb and this combination is connected to a DC source. When an iron core is inserted in the coil, what will happen to the brightness of the bulb? The Attempt at a Solution When the iron core is inserted, the magnetic field...

Hi, I'm currently writing a lab report on single phase transformers and I need to determine the equivalent circuit with respect to the secondary side. I have already found the parameters with respect to the primary side so it is just a matter of referring them to the secondary side. What I would...

Homework Statement Imagine standing on a scale and riding in an elevator at constant speed in a radial direction from the center of the Earth to a distance 3RE above the surface- I'm supposed to plot weight vs time so what I'm looking for an equation(s) I can use to find weight. *Assuming...

If I was going to build a fusion device for energy production I would build a cylinder filled with fusion fuel and the fusion would happened in the center. First it would be hard to start the fusion with relatively cold fuel. After a while of heating, the surrounding fuel would be hotter even if...

Falling matter of supernova does "work" heating the core? A supernova core collapses and the rest of the star follows, inner layers arrive first, a shock wave wave forms? As outer layers continue to collapse and slow down is there a large radial time rate change in momentum as rapidly...

I am trying very desperately to figure out this specific problem I don't need examples of other problems i need this very very specific problem before i loose my freaking mind. Please someone explain this and show me how it works I am extremely desperate. I am told this is some sort of key, I do...

Stimulated virtual W+, W- when supernova core--> neutron star? Weak interactions allow supernova core electrons and protons to convert to neutrons and neutrinos allowing (under the right conditions) the formation of a neutron star? Large numbers virtual W+ and W-bosons are produced in a short...

I have a 380V,3 phase core type transformer which is being used as AC line choke in the incomer of a VFD.As we are using only the inductance property of the transformer,I was just wondering whether we could connect R phase of the supply to any winding and then follow the phase sequence...

In the picture, I have the question and the Saha Equation. I have all the correct answers for all the variables and constants on the right side of the equation, and I've done the calculation twice, and I'm getting an answer of 1.56x10-28 That is equal to the left side, which is NII/(NI+NII). NII...

B = μ0nI Usually, the value of B is quite small... I'd like to boost the magnetic field B to a much larger and stronger field, and the most efficient way I find to do that is using a high permeability core B = ku0nI. What is the average μr of an iron core? They range from what value? Do all...

I am a newbie to physics forums and I would like to say thank you to the creators of this site because it is going to be a huge help to me and my future endeavors into physics! I honestly do not know how it took me so long to find a forum with this kind of topic as I have been a member of cloudy...

Homework Statement A ferromagnetic core is shown the figure below. The depth of the core is 5 cm. The other dimensions of the core are as shown in the figure. Find the value of the current that will produce a flux of 0.003 Wb. With this current, what is the flux density at the top of the...

Hi all, I'm working on designing a variable inductor using a ferrite core. The basic idea is that I have a large wound inductor on the central arm which I pass a DC-current through, and a smaller, variable inductor on one of the side arms. As you increase the current through the main winding...

Hi Guys, First post here. I'm just wondering if anyone could lend a helping hand in the following derivation. It is taken from Ishida AIChE J 14 (1968) 311 (also very similar to that derived by Ausman Chem Eng Sci 17 (1962) 323) and concerns the derivation of the general non-catalytic shrinking...

In case of a meltdown wouldn't large amounts of boron dust dumped over the core eat up all the free neutrons?

Assume no boron and all control rods out, so the core is super-critical. if KCODE mode is used, and F4 card is for tally the neutron for each assamblies. Can the results represent the power distribution of the core, whether the multiply-factor can affect. the results i get (power...

The question simply asks (read slowly): What fraction of the earth’s volume is the molten part of the core? I think I'm suppose to use the following equation since it has been stated in the book (though, I'm not entirely sure if I should): surface area–to–volume ratio = (surface...

Hello, I am currently working with mono phase transformers. I would like to know if there is an equation to calculate the voltage when the core saturates so I can compare with my practical results with. Thank you very much João

Is there a reason why a wire coil inside of an iron pipe wouldn't work as an electromagnet?

If so, how??

Hello, I'm trying to levitate the iron core of an electromagnet at a certain postion. How can I calculate what the minimum currennt is that I need to put on the electromagnet to prevent the core from falling out at the bottom? Is there an equation to know at what position the core will be...

Research indicates the Earth's magnetic field drives contra-rotating solid and liquid cores. Interaction between the two layers is believed to generate the Earth's magnetic field. Somehow that sounds funny, but I guess it must be so. “The magnetic field pushes eastwards on the inner core...

I know the Fuel Rods are 12 Feet long Tubes made of Zirconium Alloy. And they fill them with Uranium Oxide Pellets. And the Control Rods are inserted inbetween them to slow down the reaction. And the Control Rods are made of Boron. But is the Control Rods Tubes filled with Boron...

Hi guys, I'm wondering whether I'd be able to generate around 3V - 5V with a magnetic coil using a high turn ratio in the presence of a changing magnetic field. I know guitar coils can generally produce around 500mV - 1V, I wish to generate around 3V -5V even if it is for a very short time...

I have come across a problem which is a homework indeed, but i tried to pack this question up so that it is more theoretical. What i want to know is if i am alowed to write energy conservation for an atom which emitts a photon (when his electron changes energy for a value ##\Delta E##) like...

Lets say we put an electron in a box (spherical) which has a radius ##r##. I want to know if position uncertainty ##\Delta x = r## or is it ##\Delta x = 2r##? I need to know this to corectly calculate 1st the momentum uncertainty ##\Delta p=\frac{\hbar}{2\Delta x}## and 2nd that kinetic...

I realize this is something I should probably know intuitively, but why are core states (generally) treated relativistically in density functional calculations? What exactly makes these relativistic bound states rather than non-relativistic? I think this is some basic physics I'm forgetting.

Just wondering if anyone here got into the Kickstarter program for this. http://www.parallella.org/2013/06/29/parallella-open-source-hardware/"][/PLAIN] http://www.parallella.org/2013/06/29/parallella-open-source-hardware/ Looks very interesting, the 1st ones are being shipped out...

Solids tend to expand when heated or when they transition to a liquid. Is this thermal expansion a factor in the earth? If the diameter/volume increases, this would cause the surface area to increase also. This would lead to cracks, rifts or faults in the crust of the earth. Could this be a...

As a soon to be physics major I am about to purchase a laptop. However, I can't decide what I want. Should I go for a laptop with a dual core processor with a higher clock rate or a quad core processor with a slower clock rate. The laptop with the quad core is a bit out of my price range but I...

I have a question about solenoids. The formula for the magnetic field energy density is: \frac{1}{2}\frac{B^{2}}{μ} If I have an air-filled core, then μ=μ0. If I have a steel core, then μ will be ~ 100μ0. This implies that an air-filled core solenoid stores more energy than a steel core...

I'm trying to understand how to solve PDEs that are Sturm Liouville problems. I've read a couple of presentations about this, but I'm lost as to the implications for the solution process. Most descriptions discuss putting the second order differential equation into a Sturm-Liouville form...

Good afternoon. I have thus far taken for my math major: Linear Algebra (with proofs), Complex Analysis for Applications, Linear/Nonlinear systems of ODE, Applied Combinatorics, and Foundations of Geometry. Next year will be my 3rd year of study. However, I've yet to complete the year long...

How do i calculate the amound of windings I need to make an solonoid electro magnet with around 1 T.. I checked with google, and there seesm to be a lot of different formulaes which confusses me alot..

Hi here, I am trying to make an efficient ribbon microphone motor. My target is to get a highest possible output voltage so it can be plugged into a regular mic pre-amp. It should have possibly flat output on frequences 20Hz to 20KHz. I know that electric output depends on magnetic field...

If I have a rod with a steel core bonded to an aluminum shell, how can I find the stress in the rod when it is subjected to a temperature change? I know how to find the stress due to temp change if the tool is made of the same material throughout, but how do I do it if there are two? I...

I’m trying to find out the largest number of cores that can be used on a specific queue in LSF with the bqueues command. I’ve used the option –l after reading the manual, but I don’t see any information about cores listed. Any suggestions? Thanks.

Hi Guys, This may seem like a stupid question but if the Earth gets hotter the closer to the core you get, then why is the inner core apparently solid? Yet the outer core is liquid? They are both (inner/outer cores) made of roughtly the same stuff, and assuming pressure alone is what...

I am designing a 2D model of a three-phase core-type transformer in ANSOFT MAXWELL 14.0. While doing so I have encountered a strange problem. Start of the problem:- While designing the transformer, I wanted to incorporate core losses. So, I did the following steps:- Excitations -> Set...

Homework Statement I'm attempting to solve the constants that are attained after using separation of variables for a solid permeable prolate spheroidal core wrapped with N turns of wire using boundary conditions. H^{1}_{\delta} inside core H^{2}_{\delta} insulation H^{3}_{\delta}...

Given the same voltage and current, hence electrical power, what kind of core design can maximize the "reach" of an electromagnet? For example, with the magnet above a table, axis pointing down at the table, attempting to lift a small iron washer, is there a core design that significantly...

When we calculate magnetic field of iron core solenoid, should we multiply "relative permeability" or "effective permeability"? I thought that we should use relative permeability, but wiki(http://en.wikipedia.org/wiki/Solenoid) says that we should use effective permeability. I'm so...

This is more of a question. I don't have a background in physics as you might notice. I am looking for a little help. Why the core spins faster than the crust? At a point the earth’s rotation was much faster, both core and out layers pretty much at the same speed. Both the moon and space...

I am having trouble pinning down why the relative permeability of a transformer core will not directly affect the output voltage. In fact the voltage is determined by the turns ratio and is independent of mu of core material. Given this where is the flaw in the following reasoning: Induced...

Why is Earth's nucleus mostly made from iron?

When are the long awaited 8-core processors from AMD and Intel going to be commercially available? Will they use current sockets and chipsets or require new ones? What kind of applications would fully make use of an 8-core 16-thread processor? Certainly there aren't any PC games that would need...

Homework Statement Given a toroidal core, with known μr, minor radius R1, major radius R2, height h (the section is not a circle, but a rectangle (R2-R1)×h), placed in a magnetic field B0 with cylindrical axisymmetries (B0r=0, B0θ=0, B0z=B0), find the magnetic field resulting by the...

Hey guys, First off, I apologize if this is in the wrong section. I am currently an intern taking 6 months off from my senior year pursuing a mechanical engineering degree. Having not taken a heat transfer class yet, I am stumped as to how to go about tackling my latest project. Basically...

hello i have a question about the transformer core.when we make it's core,we usually make it laminated to reduce eddy currents.but i saw that there is a soldeing in the corner of the transformer core.why we do this ?

Hi guys, I've recently stumbled on an interesting article highlighting a point by james jean that a pinhead of 1mm (I took this to mean that it was a box of 1mm sides so 1E-9m3 volume) heated to 15 million kelvin, sun's core, could kill a person 84 miles away. I tried working this out using...